Fuel computing device



NOV. 29, 1949 COPLAN 2,489,401

FUEL COMPUTING DEVICE Filed June 3, 1947 L Ol//S CPLAN T-E E JNVENTOR A TroR/v: Y

Patented Nov. 2'9, 1949 UNITED STATES PATENT OFFICE FUEL COMPUTING DEVICE Louis Coplan, Ottawa, Ontario, Canada Application June 3, 1947, Serial No. 752,061 In Canada May 1, 1947 1 Claim. 1

This invention relates to a device for making calculations in relation to the consumption of fuel and the like.

The device has a particular application to the oil retailing business and may be particularly adapted to the computation of the rate of consumption of fuel oils and for forecasting when further deliveries to customers will have to be made. Such computations have to be made constantly by distributors of fuel oil, and formerly involved laborious arthmetical operations.

Consumers of fuel oil use the oil at different rates in proportion to the heat loss of the building being heated. The heat loss of a building depends on its size and construction, and varies with the outside temperature. The amount of fuel burned in a given heating plant will therefore vary from day to day with the outside temperature.

rIhese factors, and others, introduce many variables which make the computation of oil deliveries most tedious and require numerous arithmetical calculations. The mathematical Work associated with each delivery involves a subtraction, a division, a multiplication and a second division. In view of the large number of deliveries made by each distributor, it is obvious that some errors will inevitably be made. Further, the time involved in making such simple but numerous calculations makes up an appreciable item of cost in clerical work.

The economics of fuel delivery dictate that the largest possible quantity be placed in the consum'ers tank on each delivery. That is, it is not economical to make a delivery to a consumer when he has several days supply on hand. However, a margin of safety must be provided to take care of certain variables. If a consumer runs out of fuel the distributor runs the risk of losing him as a customer.

It is an object of this invention to provide a device by which the distributor can quickly and accurately make all necessary calculations incident to the consumption of fuel so as to plan deliveries at the optimum time, namely that time when the consumers tank will have only sufficient fuel to provide a margin of safety for variables.

An object of this invention is to provide a device by which fuel computations can be made without any resort to arithmetic or paper calculations.

This invention, a preferred embodiment of which will be described below, presupposes the use of the Degree-day delivery system which has been in general use by distributors of fuel oil for some years. The basis of this system is the Degree-day, usually abbreviated to DD.

The DDs for a particular day during the heating season is the mean Fahrenheit temperature subtracted from 65. The mean temperature is half the sum of the highest temperature of the day plus the lowest temperature of the day. The represents an assumed room temperature, and some distributors Work on an assumed room temperature of '70 in which case the mean temperature will be subtracted from 70.

For example, if the highest temperature during a given day is 48 F. and the lowest temperature during the day is 12 F., then the mean temperature is 30 F. and the number of DDs is 35.

For the purpose of using the Degree-day delivery system, the heating season is usually assumed to begin on the 1st day of September, but may begin earlier. From the first day of the heating season forward the number of DDs for each day is calculated and the result added to the accumulated DDs then existing.

It will be observed that on a colder day more DDs are added to the total of accumulated DDs than on a milder day. For a given heating system the elapsed DDs since the last filling of the tank is an index of the amount of fuel used.

As stated above the rate of consumption in a particular heating plant depends on the heat dissipation which in turn depends on the volume of space to be heated, the construction of the building, the insulation and various other factors. To make the Degree day delivery system adaptable to different heating plants, a factor must be established for each consumer. The factor usually denoted as K is defined as the number of DDs which correspond to one gallon of fuel oil in a given heating plant.

The factor K for a particular heating system is determined by dividing the number of DDs since the last filling by the number of gallons of fuel oil required to re-fill the storage tank, which represent the number of gallons of fuel oil corresponding to the number of DDs accumulated during the period that the stated amount of fuel was used.

Given the elapsed DDs and the number of gallons of fuel oil consumed during this period, the factor K is determined. This factor is then multiplied by the optimum delivery in terms of gallonage relative to the amount of storage which forms a part of the installation in the heating plant and this resultant figure is added to the accumulated. DDs at the date of delivery. The

next delivery will be made when the accumulated 'iJDs have reached this figure.

For example it will be assumed that a 275 gallon storage tank of a particular installation is filled on october 12th when the accumulated DDs number is 392. The distributor has established a 55 gallon reserve for this tank to take care of variables and the optimum delivery is therefore the remaining capacity of the tank 220` gallons.

Based on experience the distributor may set the factor K at first conservatively at 4. Multiplying the optimum delivery of 220 gallons by the K of 4, the result of 880 is added to the DDs at the last delivery, 392, giving a result of` 1,272 DDs. The next delivery will accordingly be made when the DDs reach the total of. 1,272. In the.

year in question it is estimated that the accumulated DDs will reach about this figure on November 18th, which is the date for the distributor to make the next delivery.`

When the delivery date arrives, a small discrepancy from the estimate will usually be observed. It will be assumed as an example that on the delivery date the DDs actually reach 1,295 and this particular installation takes 193 gallons. The last filling took place at 392 DDs and this lling at 1,295 DDs results in a diiference of 903 DDs, during which time 193 gallons were used. K may now be corrected to 4.7 which is again multiplied by 220 gallons and the resultant 1,034

is added to the 1,295 DDs at the date of this last filling forecasting the next filling when the DDs reach 2,329.

This invention provides means for eliminating the above calculations and the accompanying 1555 danger of mistakes.

The invention, in its preferred embodiment comprises a base structure having fitted in relation therewith a sliding scale capable of moving in a longitudinal direction and two additional scales longitudinally xed. One of the said longitudinally xed scales runs substantially parallel to the sliding scale and the other longitudinally fixed scale is inclined at an` angle to the fixed scale in plane of the base. The longitudinally fixed scales have preferably four sides with graduations thereon, and they are rotatable and geared in such a relation together that when one isvturned to expose a given side the other is automatically positioned so as to expose a corresponding side. In conjunction with the sliding scale there is preferably a fixed scale which coincides with and corresponds to the sliding scale at one point. Both the sliding scale and its corresponding fixed scale are graduated in degree-days. The four-sided scale disposed parallel to the sliding scale is graduated in gallons and the other foursided scale disposed at an angle to the sliding scale is graduated to show K, the number of degree-days corresponding to 1 gallon of fuel. A small transparent ruler is preferably used for reading the results, but other means could be substituted therefor.

A preferred embodiment of this invention will now be described with reference to the drawings.

Figure l shows a general plan view of the device as a whole with cut-away portion at three places to show the mechanism more clearly.

Figure 2 shows a front elevation view of the device corresponding to Figure 1.

Figure 3 shows a fragmentary cross-sectional view at either of the indications denoted by III-III in Figure 1.

Figure 4 shows a side elevation View of a p0rtion of the device, and corresponds to Figure 1.

The same numbers denote like parts in all gures.

Referring to Figure 1, the device is shown generally at I, having a top board 2 and a bottom board 3. The side walls are shown at 4. The sliding scale is shown at 5, graduated in degreedays, and beside it on the top board 2 is fixed degree-day scale 2l. The graduations on the DD scales 5 and 2 will be described subsequently.

Gallon scale e is rotatably mounted and is disposed parallel to sliding scale 5, and K-scale l is likewise rotatably mounted, but is placed at an angle to sliding scale 5. The magnitude of the angle and the graduations on the gallon scale B and theK scale will be described later.

As shown in Figure 2, the degree-days scale 5 is cross-shaped in section so that it can be pulled out and inserted in different positions. It is not necessary to have scale rotatable as in the case of gallon scale 6 and K-scale 1, because there is only occasional need to change the position of the degree-days scale. The iour sides of degreedays scale cover consecutively the probable elapsed degree-days for any ordinary winter; one

side will be used during the early part of the winter and by the time that spring has come the degree-days scale will have been used on its second and third sides and will in all probability have exposed its fourth side. On the other hand scales E and l are used on their different sides continuously during calculations, since the size of tank and thus also the 2 factor will vary widely for different customers.

Gallon scale 5 and K-scale 'I are mounted on shafts II and I2 respectively, having mounted thereon bevel gears, each of which bevel gears mesh with corresponding bevel gears on a common shaft, so that when the gallon scale 6 is turned so as to expose a scale having a different range, the K scale l will rotate to give a different K factor scale suitable for use with the new gallon scale. A knob Il may be fastened on shaft II at the end away from the bevel gear I3 to enable scale to be rotated and simultaneously scale Iby means of the bevel gear system subsequently described.

In this preferred embodiment, gallon scale B is mounted on shaft I I, and shaft I I is fitted with bearings 22 and 24 to allow rotation but prevent longitudinal motion. Bevel gear I3 is fixed on shaft II and is adapted to mesh with bevel gear H3A fixed on shaft I5.

K-scale 'I is similarly mounted on a shaft I2 provided with bearings as at 23 in a manner similar to gallon scale 5. The axis of shaft I2 carrying K-scale 7 is disposed at an angle to degreeday scale 5.

Bevel gear I4 iixed on shaft I2 meshes with bevel gear I9 fixed on shaft I5. Shaft I5 thus provides the connecting linkage between the two scales 6 and 'I and keeps them always in a corresponding relation to each other.

Shaft I5 is shown carried in bearings 2U and 2I. Such construction is merely exemplary, and various additions will be obvious to the manufacturer of business machines and the like. Specifically, an interval stop device may be provided, for `example by having shaft I5 fitted with foursided'block Sand by having spring means 9 to hold the shaft in one of the four alternative positions, so that itiwill not be disturbed by vibration ofthe board, orthe like, but only when knob lihas applied to it suiiicient torque to overcome the resisting moment inherentsin the intervalstop device.

Bar |70 is` preferably providedto markthe zero position on degreefday scale 'Ich the advantage of which will' be apparent when the opera-tion is described.

A peg or pin may be usedt with facilityin conjunction with scales and 21 f or markingaposition used in a given set of calculations.

The graduations employed for the` various scales will now be described'I and also the relationt whichA each scale mustV bear to theothers. In describing these scales, thelower partici the scale is intended to refer tol thatV part of the scale whichis illustrated towards the bottoml of Fig. 1, and the upper part` of4 the scale to that part of the scale whichl is illustrated` towards the top of Fig. 1. An ascending sca'lc* designatesa scale whichl shows continuousv numerical increments from the lower parli.AV of thev scale to the upper part of the scale. "I he gallon scale G is an ascending evenly calibratedscale, markedin gallons. A, convenient calibration is Y gallons to the inch, but the calibration chosen depends upon the quantity of oil involyedand as has been seen four gallon scales have been provided with different calibrations Ito p rovifl` 2ik wide range to the device. Thus one scale rn-igljit` be calibrated 5 gallons tothe inch,lapsecond scale 10 gallons,v a third and the fourth 5,0.gallons to the inch. These scales correspondingpto the fourr sides of the rotating member 6. Inleach canse the lowest quantity marked on thescale is greaterl than zero. Thus the scale with 10 gallons tothe inch might start at 100 gallons and ascendto 25.0 gallons. An essential point is thatthe zero points which would result if each of the four scaleswere extended downwards beyondy the conneS of the device must coincide. Thus if the lowestcalibration oi the ten gallon toA thev inch: scaley is., one. hundred gallons, the lowestcalibration of. the vegallon to the inch scale will beftygallons. The reason for this is that. otherwisetheslopeof the K scale 1 could not remaincpnstantand givethe desired results. The sliding, DD.scale 5 is` an ascending evenly calibrated scale.Y Eachof the foursides offthisiscale retains thesamecalibration interval but covers successiveranges, Thus a convenient calibrationwould b eoneside ofthe scale frorn'lOvGO-to .4000;at1200IDDs--to the inch, one fromv 4000. to-'10.0.0,on e from 'ZOOOto .10,000 and en@ from 10.000 toqlQO.- The Stationr-DD scale 2l is an ascending eyenlylcallbrated-gscale. with the 'same calibration interval as that chosen for scale 5. The scale however starts at zero, thus 200 DDs to theinchandr3000DDs to the scale is adopted forscaleA 5 1v scaled] wouldv run from zero to 3000. The DD scales.5'..and.21 arcwadjracent as the readings should be taken at the dividing line between the two scales for greatest accuracy. It is immaterial. provided the .K scale isA` positioned accordingly, I Whether scale 21 is placed lto theright or left ofscaler. The'Kscale 1 is positioned soastomakean-lacute angle with scale 21 asshownin rliig.` 1,n andrzso that-the zero ofthe K. scale coincides withtherzero ofthe lDD scale 21. The anglernaderbyJthe'K scale is such that if the K scale were extended downwards beyond'the limits of thendevceit would intersect theY downward extension the gallon-Y. scale at what would be the zero point of the latter if the calibration of the gallon scale were continued along the extension. (Hence is seen the importance of having the zero point of each side of 6 the gallon scale coi-ncideJ'- The K scale 1 is an aseending-scalebut unequally calibrated, the units being spaced increasingly far apart as thel scale ascends. The calibrations on--this'scale can easily be foundempirically, the procedure beingto choose a point on the gallon scale,y say 200' galilons, choose another point on the DD scale- 21, say leeDDs, divide the DDreading by the gallon scale reading to obtain the K value, in our example K would be seven. Rulethrough the points chosen on the gallon scale 81 andi the DD scaleZ'l tointersect the K scalef'l, and' makeA this point of intersection'Ywithf-the calculated K value, in this case seven. Similarly, the rest of` theK 1 scale can be calibrated the fractional'inumber being filled in by interpolation TheV distance along the l scale 1 in inchesfrom' the zero-point of scale-1 for a particular K Value may alsobeusalu culated using the relationship.

KYD. X-KY Distancefalong K scale in inches:

where It can be shown by a simple geometric proof involving similar trianglesA that if the figure chosen on the DD scaley 21 is multiplied by affactor, say

and the same K value isretained,` aline drawn through the K value and the new DDv reading will intersect the gallon scale at a.l point which representsrthe figure chosen on the gallon scale multiplied by the same factor as that. applied to the DD scale 2l. Thus to continue the example above, retaining the K factor 1 and using al DD reading of 2100, the gallon scale will be intersected at 300.

Figures 2 and 4 show elevation views corresponding to the plan view of Figure. 1, and since like numbers denote the saine partsin all figures, these will be helpful in clarifying the present descripticn.

Figure 3, shows a preferredconstruction of the scales Gand 1. In this view, therepresentation is a fragmentary. cross-sectional one, taken at either of the designations IIIMIII in Figurel the numbers shown vin Figure corresponding to Ill- III on scale 5 in Figure l. The gallon scale 0 isv shown in cross-section, and demonstrates a shape which has been found satisfactory, namely with four flat sides, and routed ork grooved with flutes-.between the flattened sides. This demonstrates the preferred construction forthe two rotating scales. The scales 6 and 1 are boredfor their entire length tor receive shafts l I and l2, a construction which seems preferable to prevent warping or distortion. To preventscales 6 and 1 frornrotating on shafts Il and l2, theshaits are pro-vided with tapped transverse holes 28 -and the scales are provided with transverse holes 3l. Studs ZSthreading into shafts ll and l2 are provided.' Other setting means may be used as one skilled in the art will be aware.

Top board 2 is provided with slots 25 above scales 6 and 1 considerably wider than one of the flat sides of either scales 6 or 1, so as to permit free rotation. Frames 26 are countersunk so as to be flush with the upper surface of top board 2, and these frames have a slot therein, the edges of which are shown at 26a, disposed a sutcient distance apart so that only the upward face of the scales are exposed, and yet free rotation is possible.

A typical operation of the device disclosed herein will now be described.

The operator of the device will establish the K f value for each customer, which in the absence of breakdowns of the customers equipment will remain sufficiently constant for practical purposes. He can ascertain this K value for a new customer, after he has made a delivery, by inquiring when this customer last had his tank lled. The operator then looks up in his records the accumulated DDs at the date of last filling. I-Ie also computes the accumulated DDs for the present delivery date which will remain constant for all calculations for that day. The operator positions a pin or peg on sliding scale 5 at the point on this scale which represents the DDs at the present delivery date e. g. 4000 and moves the sliding scale 5 until the DDs at the previous rllling appear above the bar I e. g. 3000. Ii desired the DDs which have elapsed since last lling can then be read on scale 21. Using the above gures the reading on scale 21 will be 1000. The operator then places a ruler 30 intersecting the DD scale 21 at the DDs which have elapsed since last filling, e. g. 1000 and the gallon scale at the number of gallons which have been delivered to the customer to refill his tanks, say 200. Reading across to the K scale figure ve will be obtained for this particular customer, since K is equal to the DDs elapsed divided by the number of gallons required to refill. The peg or pin referred to above can be used to support the ruler. Having obtained the K value for the customer, the optimum gallonage for the customer can easily be calculated since it represents the total capacity of his tank say 250 gallons less his reserve for variables, say 50 gallons. Thus his optimum gallonage will be 200 gallons. This and the K value can conveniently be marked on a card or in a book opposite the name of the customer.

Having obtained the K values and the optimum gallonage iigure for each customer, the device can then be used, after a customers tank has been nlled, to make rapid determinations of the DDs which will elapse before the customers tank requires refilling. This may be accomplished by placing the ruler so that it intersects the K scale at the known value in the example above ve, and the gallon scale at the optimum gallonage, e. g. 200. The DDs which will elapse before a delivery is required, in the example 1000 can be read oil on scale 21. To convert this to accumulated DDs scale is set so that the accumulated DDs or" last delivery, say 4000, appears above the bar l0. The DD reading on scale 5 adjacent to the elapsed DD reading on scale 21 will then represent the accumulated DDs at which delivery should be made. In the example this would be 5000. This may be marked on the customers card and the cards arranged in order according to the accumulated DD values at which their tanks should be refilled. Thus a glance at the cards will show which customers should have their tanks reiilled on a particular day and how much each requires.

The cards will also enable future deliveries to be predicted with some accuracy.

Gallon scale 6 is rotatable so as to provide four scales for various sizes of tanks and therefore various sizes of deliveries. K scale 1 rotates in synchronization with gallon scale 6 so as to furnish the correctl reading for various sizes of deliveries.

The device which is the subject of this invention, of which the preferred construction has been disclosed represents a substantial advance over previous devices existing in this eld, since it enables a complete calculation to be made :ln about live seconds. The resulting figures are of an accuracy limited only by the closeness with which the scales can be read since the device makes use of exact geometric relationships. This may be contrasted with the approximate figures often produced by this type of device. Its use will result in considerable savings in time to distributors of fuel oil, improved customer relationships and reduced delivery overhead.

What I claim is:

In a device of the character described and including a base supporting structure, a series of scales disposed on the upper surface of the base, and comprising an axially rotatable scale bearing a number of faces, each face being evenly calibrated to represent different ranges, each of which ranges commences at a number greater than zero, a xed scale in parallel relationship to the rotatable scale, said xed scale being evenly calibrated from zero, a second rotatable scale capable of rotation in unison with said first mentioned rotatable scale and disposed in angular relationship to the parallel scales, a mechanical linkage connecting said rotatable scales to transmit motion from one scale to the other, the zero point of the angularly disposed rotatable scale and that of the iixed scale coinciding the calibration of the second rotating scale being such that any value on the rst mentioned rotating scale and any value on the fixed scale will be in alignment with a value on the second rotating scale which value represents the quotient of the value chosen on the xed scale divided by the value chosen on the first rotating scale, provided that values are chosen on the rst rotating scale and the xed scale such that a line through them will intersect the second rotating scale, an additional scale capable of longitudinal movement calibrated in identical units to said fixed scale and disposed in the base in a parallel and adjacent relationship to the iixed scale.

L. COPLAN.

REFERENCES CITED The following references are of record in the le of this patent: 

